CO2地质封存力学问题的数值模拟方法综述

随着社会的发展，人类对化石能源的依赖导致大量的CO2排入大气层，从而引起全球变暖、海平面上升等一系列全球性气候问题。CO2地质封存是当前CO2减排最有前景的技术，但大量的CO2注入地层易诱发相应的力学问题：地表隆起变形、盖层完整性受损、断层活化等。因此，为了降低CO2地质封存带来的安全风险，理论分析、数值模拟和响应面方法等手段被应用于此类力学问题的分析中。由于数值模拟方法能够解决大尺度范围内复杂几何模型的多场耦合问题，数值模拟成为当前在CO2地质封存力学领域中应用最广泛的方法。因此，对CO2地质封存若干力学问题的数值模拟方法进行了全面的综述。首先，简要介绍了多孔介质的温度-渗流-力学-化学（THMC）多场耦合原理，并对数值模拟解决多场耦合问题的方法进行了归类。然后，详细总结了数值模拟在解决CO2地质封存力学问题方面的国内研究进展。最后，讨论了数值模拟方法在此类力学问题方面的应用缺陷，并提出了若干建议。

A review of numerical simulation methods for geomechanical problems induced by CO_2 geological storage

Due to the continuing consumption of fossil fuels, a large amount of CO2 is emitted into the atmosphere, leading to global warming, sea level rising and other global climate problems. CO2 geological storage is one of the most promising techniques for reducing CO2 emission. However, this approach may induce a series of geomechanical issues, such as ground surface deformation, damage of the cap-rock integrity and existing fault activation. In order to reduce the safety risk from the CO2 geological storage, theoretical analysis, numerical simulation and response surface method are all applied to solve these geomechanical issues. At present, numerical simulation is the most widely used option on account of its exceptional performances in solving multi-field coupling problems associated with large-scale and complex geometry model. The aim of this paper is to provide a comprehensive review of numerical analysis approaches for analyzing the geomechanical issues induced by CO2 geological storage. First, a brief introduction is given about the thermo-hydro-mechano-chemical (THMC) coupling theory of porous media, and the classifications of the numerical simulation methods for settling the multi-field coupling problems are discussed; then, a review of research status about settling geomechanical issues based on numerical modeling is presented in detail; finally, the difficulties of the numerical simulation in solving these geomechanical issues are discussed, from which several suggestions for improvement are offered.